Surface topology manipulation for performance enchancement of additively manufactured fluid-interacting components

ABSTRACT

Methods and systems for manipulating surface topology of additively manufactured fluid interacting structures, such as additively manufactured heat exchangers or airfoils, and associated additively manufactured articles, are disclosed. In one aspect, an article which interacts with a fluid is imparted with surface topology features which affect performance parameters related to the fluid flow. The topological features may be sequenced, combined, intermixed, and functionally varied in size and form to locally manipulate and co-optimize multiple performance parameters at each or selectable differential lengths along a flow path. The co-optimization method may uniquely prioritize selectable performance parameters at different points along the flow path to improve or enhance overall system performance. Topological features may include design features such as dimples, fins, boundary layer disruptors, and biomimicry surface textures, and manufacturing artefacts such as surface roughness and subsurface porosity distribution and morphology.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.17/130,916 filed Dec. 22, 2020 and titled “SURFACE TOPOLOGY MANIPULATIONFOR PERFORMANCE ENHANCEMENT OF ADDITIVELY MANUFACTURED FLUID-INTERACTINGCOMPONENTS,” which in turn claims the benefit of U.S. Provisional PatentApplication No. 62/953,051, filed Dec. 23, 2019 and titled “ADDITIVEMANUFACTURING FOR AEROSPACE APPLICATIONS,” the disclosures of which arehereby incorporated herein by reference in entirety.

STATEMENT

This invention was made with government support under Contract No.FA9300-18-P-1502 awarded by the United States Air Force AFTC/PZRB. Thegovernment has certain rights in the invention.

FIELD

The disclosure relates generally to methods and systems for manipulatingsurface topology of fluid interacting structures and the resultingstructural articles, and more specifically to methods of designingsurface topology for performance enhancement of additively manufacturedfluid interacting structures and associated additively manufacturedarticles.

BACKGROUND

Fluid interacting structures, including manifold structures whichcontain and transport fluid, and non-manifold structures whichexperience flow over a surface, are ubiquitous to fluid systems. Thesestructures can serve purposes in addition to simple fluid transfer orguidance, including flow conditioning, heat transfer, heattransportation, and heat rejection, encouraging or discouraging mixingwithin the flow, maintaining chemical stability, and many otherpurposes. Especially for heat exchangers, traditional approaches toproduction attempt to increase fluid flow performance while alsoincreasing heat transfer, or instead to optimize performance over thelength of the heat exchanger flow path. Though many historical examplesexist of methods to improve desired performance variables via surfacefeatures, such as the application of dimples to decrease drag andincrease heat transfer, the traditional approaches are limited if notunable to optimize a fluid manifold over the length of a fluid manifoldto meet design objectives for multiple variables, such as increasesfluid flow performance with increased heat transfer.

The disclosure solves these needs by improving performance over thelength of a fluid interacting surface, (such as the walls of a heatexchanger or other flow device) to meet design objectives for multiplevariables, using flow conditioning features which may manipulate oroptimize heat transfer, flow friction, turbulence, fluid temperature,fluid degradation, and/or other performance relevant parameters usingsurface topology features and manipulations of the surface topologyfeatures. Surface features may include but are not limited to: 1)features inherent to the manufacturing process and manipulable withmanufacturing parameters, such as surface roughness and subsurfaceporosity, and 2) features directly-designed into the manufacturedgeometry, such as dimples, fins, airfoil-like features, boundary layerdisruptors, any number of biomimicry designs including bird feathers,shark denticles, and fish scales. These features may be varied in size,shape, and number, and intermixed with other features for desiredperformance results.

The methods of manipulating surface topology of a fluid interactingstructure and the resulting articles are achieved by additivemanufacturing.

The phrases “additive manufacturing” and “3D printing” mean the processmanufacturing objects from 3D model data through the repeated additionof small amounts of material, usually layer upon layer.

Additive manufacturing technologies enable a large degree of designfreedom due to the method of repeatedly adding a small amount ofmaterial to build a part. Ideally, material may be added anywhere and inany amounts, meaning almost any form may be built at any size. Comparedto many other manufacturing methods, freeform surfaces, complexfeatures, and otherwise impossible features, like complex sealedinternal cavities, may be readily manufactured. This freedom allows fora designer to locally vary geometries with little restriction. With thefreedom to locally manipulate surface topology on a small scale, adesigner may then use modern engineering design tools, analysis tools,and computational methods such as generative design or topologyoptimization algorithms, like optimality criteria algorithms or geneticalgorithms, to perform analysis and design of surface features tolocally improve flow-related performance. These surface features may belocally varied across a large additive manufacturable part to optimizeperformance at every location.

Methods of designing surface topology for fluid interacting structures,such as additively manufactured heat exchangers or airfoils, aredisclosed. In one aspect, a structure which interacts with a fluid isimparted with surface topology features which affect performanceparameters related to the fluid flow. The topological features may besequenced, combined, intermixed, and functionally varied in size andform to locally manipulate and co-optimize multiple performanceparameters at each or selectable differential lengths along a flow path.The co-optimization method may uniquely prioritize selectableperformance parameters at different points along the flow path toimprove or enhance overall system performance. Topological features mayinclude design features such as dimples, fins, boundary layerdisruptors, and biomimicry surface textures, and manufacturing artefactssuch as surface roughness and subsurface porosity distribution andmorphology.

In one embodiment, a method of design for localized performanceco-optimization for every point (differential length) along a flow pathand overall performance improvement is disclosed. Generally, thedisclosure addresses, among other things, the task of imparting featuresinto a fluid interacting surface and the task of locally varying theform of the features to manipulate performance related parameters

SUMMARY

The present disclosure can provide several advantages depending on theparticular aspect, embodiment, and/or configuration.

Methods and systems for manipulating surface topology of fluidinteracting structures, such as additively manufactured heat exchangersor airfoils, and associated additively manufactured articles, aredisclosed. In one aspect, an article which interacts with a fluid isimparted with surface topology features which affect performanceparameters related to the fluid flow. The topological features may besequenced, combined, intermixed, and functionally varied in size andform to locally manipulate and co-optimize multiple performanceparameters at each or selectable differential lengths along a flow path.The co-optimization method may uniquely prioritize selectableperformance parameters at different points along the flow path toimprove or enhance overall system performance. Topological features mayinclude design features such as dimples, fins, boundary layerdisruptors, and biomimicry surface textures, and manufacturing artefactssuch as surface roughness and subsurface porosity distribution andmorphology.

In one embodiment, a method of manipulating a surface topology of anadditively manufactured article is disclosed, the method comprising:determining a set of design objectives for an article; assembling a setof candidate surface topology designs, each of the candidate surfacetopology designs comprising a candidate surface design to form a set ofcandidate surface designs; quantifying a set of performance measurementsof each of the set of candidate surface designs; categorizing the set ofcandidate surface designs with respect to the set of design objectives;selecting a first particular candidate surface design from the set ofcandidate surface designs, the first particular candidate surface designassociated with a first particular article location of the article;generating a first set of additive manufacturing specificationsassociated with the first particular article location; and additivelymanufacturing the article to satisfy the first set of additivemanufacturing specifications; wherein: an additively manufacturedarticle is produced.

In one aspect, the article is a fluid manifold. In another aspect, thefluid manifold is a Liquid Rocket Engine fluid manifold. In anotheraspect, the article is an airfoil. In another aspect, the set ofperformance measurements comprise experimentally-generated performancemeasurements. In another aspect, each of the set of candidate surfacetopology designs further comprises a candidate surface manufacturingdesign to form a set of candidate surface manufacturing designs. Inanother aspect, the method further comprises the step of selecting afirst particular candidate surface manufacturing design from the set ofcandidate surface manufacturing designs, the first particular candidatemanufacturing surface design associated with the first particulararticle location of the article. In another aspect, the method furthercomprises the steps of: selecting a second particular candidate surfacedesign from the set of candidate surface designs, the second particularcandidate surface design associated with a second particular articlelocation of the article; generating a second set of additivemanufacturing specifications associated with the second particulararticle location; and additively manufacturing the article to satisfythe second set of additive manufacturing specifications. In anotheraspect, the set of performance measurements comprise a fluid frictionloss value and a heat transfer value. In another aspect, the step ofcategorizing the set of candidate surface designs with respect to theset of design objectives comprises use of at least one of a StantonNumber value and a Darcy Friction Factor value.

In another embodiment, an article with varied surface topologysatisfying a set of article design objectives is disclosed, the articlecomprising: a first particular article location of the article, thefirst particular location having a first particular candidate surfacedesign selected from a set of candidate surface designs, the firstparticular candidate surface design having a first set of additivemanufacturing specifications satisfying the set of article designobjectives associated with the first particular article location; and asecond particular article location of the article, the second particularlocation having a second particular candidate surface design selectedfrom a set of candidate surface designs, the second particular candidatesurface design having a second set of additive manufacturingspecifications satisfying the set of article design objectivesassociated with the second particular article location; wherein: thearticle is additively manufactured using both the first set of additivemanufacturing specifications and the second set of additivemanufacturing specifications.

In another aspect, the article is a fluid manifold. In another aspect,the fluid manifold is a Liquid Rocket Engine fluid manifold. In anotheraspect, the article is an airfoil. In another aspect, the article is astructure defining an enclosed cavity, the first particular candidatesurface design formed on a first interior portion of the article and thesecond particular candidate surface design formed on a second interiorportion of the article; and the set of article design objectivescomprise: a first fluid friction loss value and a first heat transfervalue, each associated with the first interior portion of the article;and a second fluid friction loss value and a second heat transfer value,each associated with the second interior portion of the article. Inanother aspect, the article is a structure defining an enclosed cavity,the first particular candidate surface design formed on a first exteriorportion of the article and the second particular candidate surfacedesign formed on a second exterior portion of the article; and the setof article design objectives comprise: a first fluid friction loss valueand a first heat transfer value, each associated with the first exteriorportion of the article; and a second fluid friction loss value and asecond heat transfer value, each associated with the second exteriorportion of the article. In another aspect, the first particular locationfurther comprises a first particular candidate surface manufacturingdesign selected from a set of candidate surface manufacturing designs.In another aspect, the first particular location further comprises afirst particular candidate surface manufacturing design selected from aset of candidate surface manufacturing designs; and the secondparticular location further comprises a second particular candidatesurface manufacturing design selected from a set of candidate surfacemanufacturing designs. In another aspect, the first particular candidatesurface manufacturing design comprises at least one of roughnessfeatures and porosity features. In another aspect, the first particularcandidate surface design comprises at least one of dimple features andgrooved channel features.

The term “fluid” means a substance devoid of shape and yields toexternal pressure, to include liquids and gases, e.g., fuels oroxidizers in liquid or gaseous form). The fluid may be any gas, liquid,gel, slurry. In one embodiment, multiple fluids are used in multipleflow paths. Flow paths may be parallel, counter, or cross flowing toencourage or discourage heat transfer. In one embodiment, phase changeoccurs within the device.

The term “topology” means geometric properties, spatial relations, andinterrelations of geometric properties and spatial relations.

The phrase “topology optimization” means a method for optimizingmaterial layout within a given design space for a given set of boundaryconditions and constraints with the goal of maximizing systemperformance.

The term “surface” means the outer part or layer of something.

The phrase “surface design” means designs pertaining to the geometricalconfiguration of a surface, such as grooves, dimples, and the like.

The phrase “surface manufacturing design” means designs or properties ona surface that result during manufacturing, such as porosity, cracking,roughness, and the like.

The term “article” means the component to be manufactured. The articlemay be any solid material which holds form to interact with fluid flowand is compatible with one or more additive manufacturing methods,including methods where the article is not directly additivelymanufactured, but where additive manufacturing is used to impart thesurface design features, such as an additively manufactured mold withdimples. The article may take the form of a tube, channel, airfoil,fuselage or any other form which may interact with fluid. Common articlematerials include metals, ceramics, and polymers, but other materialsare possible. The method of additive manufacturing allows for a minimumfeature size of proper scale relative to the size of the flow pathcross-section, such that a multiplicity of features may be patternedacross the fluid-interacting surface(s).

The phrases “at least one”, “one or more”, and “and/or” are open-endedexpressions that are both conjunctive and disjunctive in operation. Forexample, each of the expressions “at least one of A, B and C”, “at leastone of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B,or C” and “A, B, and/or C” means A alone, B alone, C alone, A and Btogether, A and C together, B and C together, or A, B and C together.

The term “a” or “an” entity refers to one or more of that entity. Assuch, the terms “a” (or “an”), “one or more” and “at least one” can beused interchangeably herein. It is also to be noted that the terms“comprising”, “including”, and “having” can be used interchangeably. Theterm “automatic” and variations thereof, as used herein, refers to anyprocess or operation done without material human input when the processor operation is performed. However, a process or operation can beautomatic, even though performance of the process or operation usesmaterial or immaterial human input, if the input is received beforeperformance of the process or operation. Human input is deemed to bematerial if such input influences how the process or operation will beperformed. Human input that consents to the performance of the processor operation is not deemed to be “material”.

The terms “determine”, “calculate” and “compute,” and variationsthereof, as used herein, are used interchangeably and include any typeof methodology, process, mathematical operation or technique.

The term “means” as used herein shall be given its broadest possibleinterpretation in accordance with 35 U.S.C., Section 112, Paragraph 6.Accordingly, a claim incorporating the term “means” shall cover allstructures, materials, or acts set forth herein, and all of theequivalents thereof. Further, the structures, materials or acts and theequivalents thereof shall include all those described in the summary,brief description of the drawings, detailed description, abstract, andclaims themselves.

The term “module” as used herein refers to any known or later developedhardware, software, firmware, artificial intelligence, fuzzy logic, orcombination of hardware and software that can perform the functionalityassociated with that element.

The phrase “graphical user interface” or “GUI” means a computer-baseddisplay that allows interaction with a user with aid of images orgraphics.

The term “computer-readable medium” as used herein refers to any storageand/or transmission medium that participate in providing instructions toa processor for execution. Such a computer-readable medium is commonlytangible, non-transitory, and non-transient and can take many forms,including but not limited to, non-volatile media, volatile media, andtransmission media and includes without limitation random access memory(“RAM”), read only memory (“ROM”), and the like. Non-volatile mediaincludes, for example, NVRAM, or magnetic or optical disks. Volatilemedia includes dynamic memory, such as main memory. Common forms ofcomputer-readable media include, for example, a floppy disk (includingwithout limitation a Bernoulli cartridge, ZIP drive, and JAZ drive), aflexible disk, hard disk, magnetic tape or cassettes, or any othermagnetic medium, magneto-optical medium, a digital video disk (such asCD-ROM), any other optical medium, punch cards, paper tape, any otherphysical medium with patterns of holes, a RAM, a PROM, and EPROM, aFLASH-EPROM, a solid state medium like a memory card, any other memorychip or cartridge, a carrier wave as described hereinafter, or any othermedium from which a computer can read. A digital file attachment toe-mail or other self-contained information archive or set of archives isconsidered a distribution medium equivalent to a tangible storagemedium. When the computer-readable media is configured as a database, itis to be understood that the database may be any type of database, suchas relational, hierarchical, object-oriented, and/or the like.Accordingly, the disclosure is considered to include a tangible storagemedium or distribution medium and prior art-recognized equivalents andsuccessor media, in which the software implementations of the presentdisclosure are stored. Computer-readable storage medium commonlyexcludes transient storage media, particularly electrical, magnetic,electromagnetic, optical, magneto-optical signals.

Moreover, the disclosed methods may be readily implemented in softwareand/or firmware that can be stored on a storage medium to improve theperformance of: a programmed general-purpose computer with thecooperation of a controller and memory, a special purpose computer, amicroprocessor, or the like. In these instances, the systems and methodscan be implemented as program embedded on personal computer such as anapplet, JAVA.RTM. or CGI script, as a resource residing on a server orcomputer workstation, as a routine embedded in a dedicated communicationsystem or system component, or the like. The system can also beimplemented by physically incorporating the system and/or method into asoftware and/or hardware system, such as the hardware and softwaresystems of a communications transceiver.

Various embodiments may also or alternatively be implemented fully orpartially in software and/or firmware. This software and/or firmware maytake the form of instructions contained in or on a non-transitorycomputer-readable storage medium. Those instructions may then be readand executed by one or more processors to enable performance of theoperations described herein. The instructions may be in any suitableform, such as but not limited to source code, compiled code, interpretedcode, executable code, static code, dynamic code, and the like. Such acomputer-readable medium may include any tangible non-transitory mediumfor storing information in a form readable by one or more computers,such as but not limited to read only memory (ROM); random access memory(RAM); magnetic disk storage media; optical storage media; a flashmemory, etc.

The preceding is a simplified summary of the disclosure to provide anunderstanding of some aspects of the disclosure. This summary is neitheran extensive nor exhaustive overview of the disclosure and its variousaspects, embodiments, and/or configurations. It is intended neither toidentify key or critical elements of the disclosure nor to delineate thescope of the disclosure but to present selected concepts of thedisclosure in a simplified form as an introduction to the more detaileddescription presented below. As will be appreciated, other aspects,embodiments, and/or configurations of the disclosure are possibleutilizing, alone or in combination, one or more of the features setforth above or described in detail below. Also, while the disclosure ispresented in terms of exemplary embodiments, it should be appreciatedthat individual aspects of the disclosure can be separately claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be readily understood by the following detaileddescription in conjunction with the accompanying drawings, wherein likereference numerals designate like elements. The elements of the drawingsare not necessarily to scale relative to each other. Identical referencenumerals have been used, where possible, to designate identical featuresthat are common to the figures.

FIG. 1 shows a schematic diagram of one embodiment of a system formanipulating surface topology of fluid-interacting structures;

FIG. 2 shows a flowchart of one method of operation of the system formanipulating surface topology of fluid interacting structures of FIG. 1;

FIG. 3 shows a more detailed flowchart of some aspects of the method ofoperation of the system for manipulating surface topology of fluidinteracting structures of FIG. 2 ;

FIG. 4A shows a see through perspective end view of a first candidatesurface design applied within a cooling channel of the system formanipulating surface topology of fluid-interacting structures of FIG. 1;

FIG. 4B shows a cut-away side view of the first candidate surface designof FIG. 4A;

FIG. 4C shows a cut-away side perspective view of the first candidatesurface design of FIG. 4A;

FIG. 4D shows a see through perspective side view of the first candidatesurface design of FIG. 4A;

FIG. 4E shows an end view of a second candidate surface design appliedwithin a cooling channel of the system for manipulating surface topologyof fluid-interacting structures of FIG. 1 ;

FIG. 4F shows a cut-away side view of the second candidate surfacedesign of FIG. 4E;

FIG. 4G shows a cut-away side perspective view of the first candidatesurface design of FIG. 4E;

FIG. 4H shows a see through perspective side view of the first candidatesurface design of FIG. 4E;

FIG. 4J shows a perspective end view of a third candidate surface designapplied within a cooling channel of the system for manipulating surfacetopology of fluid-interacting structures of FIG. 1 ;

FIG. 4K shows a cut-away side view of the third candidate surface designof FIG. 4J;

FIG. 4L shows a cut-away side perspective view of the third candidatesurface design of FIG. 4J;

FIG. 4M shows a see through perspective side view of the third candidatesurface design of FIG. 4J;

FIG. 4P shows a perspective end view of a fourth candidate surfacedesign applied within a cooling channel of the system for manipulatingsurface topology of fluid-interacting structures of FIG. 1 ;

FIG. 4Q shows a cut-away side view of the fourth candidate surfacedesign of FIG. 4P;

FIG. 4R shows a cut-away side perspective view of the fourth candidatesurface design of FIG. 4P;

FIG. 4S shows a see through perspective side view of the fourthcandidate surface design of FIG. 4P;

FIG. 4T shows a perspective end view of a fifth candidate surface designapplied within a cooling channel of the system for manipulating surfacetopology of fluid-interacting structures of FIG. 1 ;

FIG. 4U shows a cut-away side view of the fifth candidate surface designof FIG. 4T;

FIG. 4V shows a cut-away side perspective view of the fifth candidatesurface design of FIG. 4T;

FIG. 4W shows a see through perspective side view of the fifth candidatesurface design of FIG. 4T;

FIG. 5 shows a categorization table relative to a set of four candidatesurface designs;

FIG. 6 shows a comparison graph of pressure drop vs. average walltemperature for a set of ten (10) candidate surface designs, eachcandidate surface design applied within a cooling channel;

FIG. 7 shows a comparison graph of Stanton Number vs. Darcy FrictionFactor for a set of ten (10) candidate surface designs, each candidatesurface design applied within a cooling channel;

FIG. 8 shows a comparison graph of Wall Temperature vs. Axial Positionfor a set of three (3) swirl inducing channel designs, each candidatesurface design applied within a cooling channel;

FIG. 9A shows a cut-away side view of one embodiment of a Liquid RocketEngine with portions additively manufactured using the system formanipulating surface topology of fluid-interacting structures of FIG. 1;

FIG. 9B is another cut-away side view of the Liquid Rocket Engine ofFIG. 9A;

FIG. 9C is a close-up perspective view of a portion of the Liquid RocketEngine of FIG. 9A;

FIG. 9D is another close-up perspective view of a portion of the LiquidRocket Engine of FIG. 9A;

FIG. 9E is another close-up perspective view of a portion of the LiquidRocket Engine of FIG. 9A;

FIG. 10A is a perspective view of an airfoil with portions additivelymanufactured using the system for manipulating surface topology offluid-interacting structures of FIG. 1 ;

FIG. 10B is another perspective view of the airfoil of FIG. 10B; and

FIG. 10C is a side view of the airfoil of FIG. 10A.

It should be understood that the proportions and dimensions (eitherrelative or absolute) of the various features and elements (andcollections and groupings thereof) and the boundaries, separations, andpositional relationships presented there between, are provided in theaccompanying figures merely to facilitate an understanding of thevarious embodiments described herein and, accordingly, may notnecessarily be presented or illustrated to scale, and are not intendedto indicate any preference or requirement for an illustrated embodimentto the exclusion of embodiments described with reference thereto.

DETAILED DESCRIPTION

Reference will now be made in detail to representative embodiments. Thefollowing descriptions are not intended to limit the embodiments to onepreferred embodiment. To the contrary, it is intended to coveralternatives, modifications, and equivalents as can be included withinthe spirit and scope of the described embodiments as defined, forexample, by the appended claims.

FIG. 1 shows a schematic diagram of one embodiment of a system formanipulating surface topology of fluid-interacting structures 10. Thesystem for manipulating surface topology of fluid-interacting structures10 may also be referred to as surface topology system, surface topologymanipulation system, or simply system.

The surface topology manipulation system 10 generally considers anddetermines a set of article design objectives 20, consults or referencesreference sources 30 as may be required, performs a surface topologymanipulation method 100, and generates or produces surface designspecifications and/or surface manufacturing design specifications(collectively, additive manufacturing specifications 110) which areprovided to an additive manufacturing production system 40 which usesthe additive manufacturing specifications 110 to create or manufacture aproduced article 50.

The article design objectives 20 may include cooling objectives such asheat transfer values, flow performance objectives such as degree ofturbulent or laminar flow, friction values, average wall temperature(for enclosed systems such as cooling channels), pressure drops. Notethat the article design objectives 20 may be fixed across the entirearticle or may vary along or within the article. For example, a set ofarticle design objectives for a cooling channel article may comprise afixed value or maximum value for pressure drop along the entirelongitudinal (axial) length of the cooling channel yet may have a firstfriction value at a first article location and a second friction valueat a second article location. The article design objectives 20 maycomprise set values, a range of maximum and minimum values, not toexceed maximum values, not to drop below minimum values, and any type ofdesign objectives known to those skilled in the art.

In one embodiment, one or more of the article design objectives 20 arearticle design requirements. The phrase “design objective” means atargeted design value that is ideally achieved but is not required to beachieved. The phrase “design requirement” means a targeted design valuethat is required to be achieved.

The surface topology manipulation method 100 is described in more detailwith respect to FIGS. 2 and 3 below.

The additive manufacturing production system 40 may be any additivemanufacturing system known to those skilled in the art.

The produced article 50 may be any article which engages with fluid, toinclude, for example, a cooling channel, a cooling channel of a LiquidRocket Engine (LRE) such as described in FIGS. 9A-E, and an airfoil, asdescribed in FIGS. 10A-C.

FIG. 2 shows a flowchart of one method of operation of the system formanipulating surface topology of fluid-interacting structures 200 ofFIG. 1 . The method of operation of the system for manipulating surfacetopology of fluid-interacting structures 200 may also be referred to asthe surface topology method, the surface topology manipulation method,the manipulation method, or simply as the method.

In one embodiment of the surface topology manipulation method 200, thesystem for manipulating surface topology of fluid-interacting structures10 of FIG. 1 follows the sequence of steps described in FIG. 2 . Othermethods of use are possible, to include a sequence of steps differentthan those of FIG. 2 , a sequence with additional steps, and a sequencewith fewer steps. Also, as will be clear from the below description,elements of the system 10 of FIG. 1 , and/or other aspects of a systemas described in this disclosure, may be incorporated.

With particular attention to FIG. 2 , a flowchart of surface topologymanipulation method 200 is provided, the method 200 utilizing theelements described in the systems of FIG. 1 .

The method 200 starts at step 204 and ends at step 232. Any of thesteps, functions, and operations discussed herein can be performedcontinuously and automatically. In some embodiments, one or more of thesteps of the method 200 may comprise computer control, use of computerprocessors, and/or some level of automation. The steps are notionallyfollowed in increasing numerical sequence, although, in someembodiments, some steps may be omitted, some steps added, and the stepsmay follow other than increasing numerical order.

At step 208, the surface topology manipulation method 200 receives a setof design objectives for the article, as described above. The designobjectives may be a set of design objectives and may comprise valuesfixed for the entire article or variable with location on or within thearticle. After completion of step 208, the method 200 continues to step212.

At step 212, the method consults reference sources as may beappropriate. For example, the method may consult operating proceduresfor the particular type of additively manufacturing production system 40employed, so as to achieve one or more targeted design objectives.

In one aspect, a designer may access one or more reference guides whichcontain test data of many features at different sizes in different flowregimes. The designer may choose different features and sizes fordifferent points along the article's flow path to elicit the desiredperformance at every differential length along the flow path. Thedesigner may functionally vary the form of the features along the path,or may intermix features at the same scale, such as interspaced dimplesand fins, or intermix features at different scales, such as fins withsmall dimples on them. In another aspect, a designer may useComputational Fluid Dynamics to simulate the flow in the device anditeratively impart features into the design to locally optimizeperformance over multiple simulations.

After completion of step 208, the method 200 continues to step 216.

At step 216, the method 200 performs the surface topology manipulationmethod, as described in more detail with respect to FIG. 3 below. Aftercompletion of step 208, the method 200 continues to step 220.

At step 220, the method 200 established surface design specificationsand/or surface manufacturing design specifications (collectively, theadditive manufacturing specifications 110) that define the surfacetopology defined or selected in step 216. After completion of step 220,the method 200 continues to step 224.

At step 224, the method 200 provides the complete set of additivemanufacturing specifications 110 to the additive manufacturing system40. After completion of step 224, the method 200 continues to step 228.

At step 228, the method 200, by way of the additive manufacturing system40 with use of the complete set of additive manufacturing specifications110, produces the additive manufactured article. After completion ofstep 228, the method 200 ends at step 232.

FIG. 3 shows a more detailed flowchart of some aspects of the method ofoperation of the system for manipulating surface topology offluid-interacting surfaces of FIG. 2 . More specifically, FIG. 3 expandson the step 216 of FIG. 2 . In one embodiment of the method 300 of FIG.3 , the method 300 follows the sequence of steps described in FIG. 3 .Other methods of use are possible, to include a sequence of stepsdifferent than those of FIG. 3 , a sequence with additional steps, and asequence with fewer steps. Also, as will be clear from the belowdescription, elements of the system 10 of FIG. 1 , and/or other aspectsof a system as described in this disclosure, may be incorporated.

The method 300 starts at step 304 and ends at step 332. Any of thesteps, functions, and operations discussed herein can be performedcontinuously and automatically. In some embodiments, one or more of thesteps of the method 200 may comprise computer control, use of computerprocessors, and/or some level of automation. The steps are notionallyfollowed in increasing numerical sequence, although, in someembodiments, some steps may be omitted, some steps added, and the stepsmay follow other than increasing numerical order.

At step 308, the method 300 assembles a set of candidate surfacetopology designs. Each candidate surface topology design may include asurface design and/or a surface manufacturing design. Generally, asurface design refers to geometrical shapes or patterns on the surfaceor just below the surface, such as dimples, anti-dimples, etc. asdescribed elsewhere in the disclosure. Generally, a surfacemanufacturing design refers to features imparted to the article surfaceby the additive manufacturing process, such as surface porosity, surfaceroughness, surface cracking etc. as described elsewhere in thedisclosure. FIGS. 4A-D present an example set of four (4) surfacedesigns, each for a cooling channel application. After completion ofstep 308, the method 300 continues to step 312.

At step 312, the method 300 quantitatively describes each of the set ofcandidate surface topology designs, such as by flow performance, heatloss, etc. FIG. 5 presents an example of quantitative description of theexample set of four (4) surface designs presented as FIGS. 4A-D. Aftercompletion of step 312, the method 300 continues to step 316.

At step 316, the method 300 categorizes each of the candidate surfacetopology designs. FIG. 5 presents an example such categorization for theset of four (4) surface designs of FIGS. 4A-D. After completion of step316, the method 300 continues to step 320.

At step 320, the method 300 selects a particular surface topology designfor a particular article location (e.g., for a particular axial locationwithin a cooling chamber) from the set of candidate surface topologydesigns. As provided in FIG. 5 , a ranking score 528 is presented whichenables the selection of a particular surface topology design (here, theDesign A 512). After completion of step 320, the method 300 continues tostep 324.

At step 324, the method 300 establishes or generates a set of surfacedesign specifications and/or surface manufacturing design specifications(collectively, additive manufacturing specifications 110) for aparticular article location. (Note that the set of additivemanufacturing specifications 110 are provided to the additivemanufacturing production system 40). After completion of step 324, themethod 300 continues to step 328.

At step 328, the method 300 queries as if additional particular articlelocations are manipulated for surface topology. (An article may havedifferent performance-related needs at different points along a flowpath or in different flow paths). If the response is YES, the method 300continues to step 320. If the response is NO, the method 300 continuesto step 332 and ends.

To illustrate a scenario in which more than one particular articlelocations are manipulated for surface topology, consider e.g., a liquidrocket engine with a counterflowing regenerative heat exchanger. Therocket engine consists of a combustion chamber, a throat, and anexpansion nozzle which contain the combustion, create supersonic flow,and expel combustion products through the nozzle. A heat exchanger linesthe outside of the engine, flowing from the nozzle, past the throat, andpast the combustion chamber, counter to the direction of combustedpropellant flow. The engine is heated by the combustion flow, which isby far its hottest at the throat. The engine will perform better withhotter combustion; however, it is possible that heat from combustionwill melt the engine wall or degrade the coolant on the other side. Theengine will also perform better with reduced flow friction.

For the combustion flow, a designer may want to choose features whichboth decrease flow friction and insulate against heat transfer toprevent overheating of the engine structure. At the throat, whereheating is the greatest, the designer would prioritize the featureswhich insulate against heat transfer over those which decrease flowfriction.

For the coolant flow, the designer may want features which both decreaseflow friction and increase heat transfer. The designer would prioritizefeatures which increase heat transfer at the throat to provide the mosteffective cooling. In a truly optimal design, functional variation ofform and intermixing of features would both minimize flow friction asmuch as possible and create an overall thermal profile such that themaximum material performance is used at every differential length.Knowing how the material performance degrades with temperature, how thestrength needed to contain a constant pressure flow varies with pipediameter (larger diameter needs more strength) and the geometry of thedevices, the thermal profile can be designed such that the same materialstrength margin (factor of safety) can be used at all points along thelength of the device, despite a different temperature and diameter ateach differential length of the combustion flow path, using smoothfunctional variation of the features.

In this optimization there are more complex considerations including howcooling performance decreases as coolant temperature increases (i.e., asthe coolant is used for cooling), phase change of a liquid coolant in toa gas, and the different cooling performance in the liquid, boilingliquid, and gas regimes. Even with these additional complex effects, itis possible through multiple methods for a designer to arrive at aco-optimization of every differential length, resulting in totaloptimization of the system. In another embodiment, a similarco-optimization or pareto-optimization is performed for differentparameters of concern which may have different profiles along adifferent manifold configuration. A similar philosophy of optimizationwith differing priorities will drive the co-optimization to a similarstate regarding parameters of interest.

FIGS. 4A-D, 4E-H, 4J-M, 4P-S, and 4T-W show a sequence of five (5)candidate surface designs, each applied within a cooling channel.

FIGS. 4A-D depict a first design 410, termed a boundary scoop design.The design 410 comprises a series of twisted rings 411 extending from aninterior surface of the cooling channel.

FIGS. 4E-H depict a second design 420, termed a constant fin design. Thedesign 420 comprises a series of fins 421 extending from an interiorsurface of the cooling channel.

FIG. 4J-M depict a third design 430, termed a corrugated design. Thedesign 430 comprises a series of expansions and contractions 431 to theinterior diameter of the cooling channel.

FIG. 4P-S depict a fourth design 440, termed a dimple design. The design440 comprises a series of dimples 441 that extend into an interiorsurface of the cooling channel.

FIG. 4T-W depict a fifth design 450, termed a multi-fin design. Thedesign 450 comprises a series of fins 451 extending from an interiorsurface of the cooling channel.

FIG. 5 shows a categorization table relative to a set of four candidatesurface designs of as against a reference additively manufactured (AM)channel. The four candidate surface design columns provide quantitativevalues associated with each of the four designs. The four designs areprovided as a set of four rows.

The four designs as presented as: first row as design A 512, second rowas design B, third row as design C, and fourth row as design D 518.Column two provides a value of decrease in delta Pressure or dP, a ratioof the particular advanced concept value to the traditional geometryvalue. For example, the value of 3.28 (intersection of row 512 andcolumn 522) is the pressure drop of design A divided by the pressuredrop of the reference AM cylindrical channel. Because design A had amuch higher pressure drop, the ratio is greater than 1 (i.e., actualvalue of 3.28); this is undesirable because an increase in pressure dropis undesirable for the system, per design objectives. A value of lessthan 1 (indicating that the advanced concept had a lower pressure dropthan the traditional geometry) is desirable (for the Decrease dPcolumn). For example, with reference to the intersection of row 514 andcolumn 522, a value of dP of 0.60 is provided for design B. The samelogic applies for the “Decrease C” column—the values in this column area ratio of the advanced concept total carbon deposition and thetraditional geometry total carbon deposition. A value of less than onemeans the advanced concept deposited less carbon, a desirable attribute.A value greater than one means the advanced concept deposited morecarbon than the traditional geometry, an undesirable attribute. For the“Increase Nu” column, the relative value to 1 is reversed, meaning thatvalues greater than 1 are desirable. An increase in Nusselt Number was adesign objective for the advanced concepts as it indicates an increasein heat transfer relative to the baseline traditional AM cylindricalchannel (a value less than 1 is undesirable as it indicates a decreasein heat transfer when compared to the traditional geometry). Column 528provides a relative score of the four designs based on a selectableweighting of each of the associated three quantitative values (decreasein dP, increase in Nu, and decrease in C). The value of 1 for design Aindicates that it is the superior design in the illustrated scenario andtherefore would become the selected surface design for the set of fourcandidate surface designs considered.

FIG. 6 shows a comparison graph of pressure drop vs. average walltemperature for a set of nine (9) candidate surface designs, eachcandidate surface design applied within a cooling channel. The resultswere experimentally obtained by flowing RP-2 kerosene fuel through aresistively heated cooling channel with thermocouples spaced along thelength and pressure measurements taken at the article entrance and exit.The nine (9) candidate surface designs (designs 6.1 through 6.9) arecompared against baseline drawn cylinder design 6.0.

The average wall temp (from 8 thermocouples) and average pressure dropare shown without major outliers. The baseline design, marked with ashort dash, is an additively manufactured tube with a plain circularcross-section. Designs to the left of the baseline design showedimproved pressure loss, designs below it show improved heat transfer.The dashed curve shows a pareto front, highlighting the most optimaldesigns in the design space. This assumes that the designs arecomparable 1-to-1, which is an approximation due to variation inhydraulic diameter between the tested article design.

FIG. 7 shows a comparison graph of Stanton Number vs. Darcy FrictionFactor for a set of nine (9) candidate surface designs, each candidatesurface design applied within a cooling channel. The results werecalculated from the experimentally obtained results in FIG. 6 usinggeometric information about the article designs. Like FIG. 6 , the nine(9) candidate surface designs (designs 6.1 through 6.9) are comparedagainst baseline drawn cylinder design 6.0.

Stanton number vs Darcy friction factor may be used for comparingnon-dimensional fluid parameters for the set of candidate flow tubedesigns. Stanton number is the ratio of heat input into a fluid to theheat capacity. Darcy friction factor normalizes pipe/channel flowfriction given hydraulic diameter, relative roughness, and Reynoldsnumber. Similar to the plot of wall temp vs dP in FIG. 6 , the shortdash marker is the baseline design, a plain additively manufacturedcylindrical tube. Ideal designs increase Stanton number and decreaseDarcy friction factor. The pareto front (dashed curve) identifiesdesigns that co-optimize Stanton number and Darcy friction factor.

It is noted that the hydraulic diameter of an article is an averagevalue and that abstracted numbers may not be perfectly representative.It is also noted that the non-normalized values in FIG. 6 may beinfluenced by variations in electrical resistivity, variations in wallthickness, and other factors like different average hydraulic diameters.

FIG. 8 shows a comparison graph of wall temperature vs. axial positionfor a set of three (3) swirl inducing channel designs, each candidatesurface design applied within a cooling channel. The results wereexperimentally obtained. The set of three (3) designs are a subset ofthe designs of FIGS. 6 and 7 , i.e., designs 6.4, 6.6, and 6.7. Walltemperature at eight (8) thermocouple locations (½ inch spacing) fordifferent swirling designs are presented. The single run of the variableswirl is compared with an average 10 runs for other swirling designs.Over 20 runs total, the two constant swirl designs (designs 6.6 and 6.7)show an expected temperature increase of 60-70 deg F/in along the lengthof the tube. The baseline variable swirl design 6.4, which tightens thehelical pitch by a factor of 3 at the midpoint, shows 60 deg F/intemperature increase across the first 4 thermocouples, as expected, butshows a temperature decrease of 11 deg F/in after the fourththermocouple, indicating a much higher rate of heat transfer after thefourth thermocouple. The net trend for temperature increase across thisarticle is about half the expected value for a constant pitch helix.

It is unsurprising that the trend over the latter 4 thermocouples showeda decrease in wall temperature (a goal of such localized variations maybe to evenly balance the wall temperature by functionally grading thevariations). In the case of the presented test article, a surfacetopology design featuring a helix with pitch decreasing at a functionalrate along the tube length could create an even wall temperature alongthe length of the tube. Assuming the heat input along the wall is even,the increasing rate of swirl may be matched to the increase intemperature of the cooling fluid as it flows along the channel. In areal liquid rocket engine wall, functional variations such as these maybe used to maintain even wall temperature and minimize hot spots.

It is evident that variations within a single design have significantlocalized effects across lengths as short as 1-2 inches within a coolingchannel with hydraulic diameter of approximately 0.03 inches and wallthickness of approximately 0.1 inches. Therefore, the functional gradingand intermixing of different surface topology designs may optimize formaximized heat transfer or for minimized pressure drop at differentlocations along the same cooling channel. Further investigation withmore localized investigation of performance variables is expected showmore localized control. This expectation has been verified byComputational Fluid Dynamics.

FIGS. 9A-E depicts a sequence of views of a Liquid Rocket Engine 900with portions 910 additively manufactured using the system formanipulating surface topology of fluid manifolds of FIG. 1 . Morespecifically, FIGS. 9A-E depict one embodiment of a liquid rocket engineregenerative heat exchanger with surface topology manipulations designedto elicit different performance at different locations along the flowpath.

In laboratory experimentation examining flow friction and heat transferperformance of a rocket fuel through a rocket engine-like cooling tube,under rocket engine-like heating and flow conditions, many differentperformance capabilities were observed using different features. Certainfeatures increased or decreased both flow friction and heat transfer byvarying amount. Variation of a feature along the length of the coolingtube was shown to drive different performance at different locationsalong the tube. The laboratory study has shown that key performanceparameters can be co-optimized using intentional manipulation of thesurface topology of a cooling tube. This co-optimization orpareto-optimization can be variable at any point along the flow pathdepending on the parameters and the priorities of optimization.Individual features without variation have shown a combined performancechange of 30%-40% to both parameters of interest. Other experimentationshowed performance change in excess of 150% to one parameter, withvariable effects on the other. For the two studied parameters flowfriction and heat transfer, increases to both, decreases to both, andboth combinations of increase to one, decrease to the other wereobserved using different features.

Generally, the rocket engine with heat exchanger 900 of FIGS. 9A-Ecomprises topological surface features which interact with fluid flowsdesigned and imparted into relevant fluid-interacting surfaces of thestructure to manipulate chosen performance parameters. The structure ofthe rocket engine consists of a combustion chamber, throat, and nozzleconcentric to a circular array of many cooling channels. The outer wallof the combustion chamber, throat, and nozzle is shared with the innerwalls of the cooling channels. In this case, the chosen performancegoals are to create a uniform strength distribution over the entire wallby way of generating a specific temperature profile along the length ofthe wall, and to minimizing frictional pressure losses in the fluid inthe cooling manifold as much as possible while still addressing theprimary goal of temperature distribution.

In the embodiment of FIGS. 9A-E, the cooling fluid is also the fuelwhich is combusted in the engine. It is generally beneficial tocombustion to pre-heat propellant so long as it is not heated to thepoint that it chemically degrades and is an additional benefit to systemperformance which can be maximized and balanced with thermally induceddegradation of the fuel by the topological surface features.

An alternative embodiment to a heat exchanger may instead be a hydrofoilwhich attempts to minimize skin-friction while also minimizingmanufacturing cost using simple features where a lower level ofoptimization provides a cost-benefit over areas with less complex fluidinteractions, or any system with fluid-structure interaction and goalswhich can be maximized, minimize, or optimized in combination forgreater performance of the overall system.

Inside the rocket engine chamber, combustion is driven by the continuousinjection of propellant into an already combusting mixture. Combustedpropellants are driven through the throat, which forces flow to becomesupersonic, and flow expands and accelerates as it exists the nozzle.The walls contacting the combusted propellants along the entire lengthof the chamber, throat, nozzle structure feature a surface texture whichminimized heat transfer into the wall and the surfaces is post-processedto decrease roughness to minimize heat transfer into the wall from thecombusted propellant flow. Counterflowing to the combustion is thecoolant flow, which is also the fuel that eventually is consumed bycombustion. The coolant flows counter to the direction of the combustionflow in the cooling channels. While passing over the nozzle, a texturewhich decreases the rate of heat transfer is graded into a texture whichincreases the rate of heat transfer to provide cooling such that thetemperature profile of the wall provides a consistent structural marginover the variable diameter of the nozzle. As the coolant passes over thethroat, features which greatly increase heat transfer are used, as thethroat is typically the hottest part of the engine and demands the mostcooling, and the features may be graded to elicit the desiredtemperature profile over the length of the throat.

After passing the throat, the coolant has boiled entirely. The nowgaseous coolant then passes over the combustion chamber, which hasfeatures designed for heat transfer, and that increase in size to drivethe same amount of heat transfer as the coolant temperature increases asit flows over the length of the combustion chamber. Due to the decreasedcooling capability of a gas, larger features 920 are used to cool thecombustion chamber than are used to cool the nozzle. Feature 910 arevariable fins, feature 920 are variable dimples, and feature 930 arevariable anti-dimple.

FIGS. 10A-C depict a sequence of views of an airfoil with portionsadditively manufactured using the system for manipulating surfacetopology of fluid-interacting structures of FIG. 1 . More specifically,FIGS. 9A-E depict one embodiment of a liquid rocket engine regenerativeheat exchanger with surface topology manipulations designed to elicitdifferent performance at different locations along the flow path.

In the design of the airfoil 1000 of FIGS. 10A-C, a designer isattempting to manipulate the surface topology of an airfoil to increaselift and decrease parasitic drag. The designer may choose to achievesuch design objectives by minimizing drag over the front and across thebottom of the airfoil, while increasing drag over the top of the airfoilto increase lift. Parameters used to characterize such an airfoil mayinclude coefficient of lift, coefficient of drag, skin frictioncoefficient, pressure, temperature, and velocity of the fluid,turbulence, local values or local averages of these values, or other,general trends including flow separation from the airfoil, and others.

For the case of an airfoil, which is meant to operate under many flowregimes and different angle, the designer would choose a range of stableangles of attack and a range of flow velocities to analyze the airfoilusing simulation or other computational or test based methods. Aftercharacterizing the baseline airfoil performance, the designer selectslocal sizes for topological features at certain points along the airfoilusing a computational method which considers all the simulationsperformed, and functionally grades between the locally selected featuresand sizes. Sizes may correlate with local geometry of the airfoil or anyparameter used in characterization.

For this optimization of lift and parasitic drag, one configuration oftopological features may be thin fins/flow guides along the front 1010and bottom 1040, which change to dimples 1020 across the top. Thedimples 1020 functionally vary in size to target a local averageperformance across the many angles of attack and flow regimes withconsideration for staying within certain performance bounds for highangle of attack and/or low or transitional Reynolds number flow caseswhich may have more unique flow phenomena. The purpose of the dimples1020 is to increase and locally control lift generation, the purpose ofthe thin fins 1010, 1040 is to reduce parasitic drag by conditioning ofthe boundary layer and guiding the flow direction at the boundary layer.The designer may also use the thin fins in an area along the top of theairfoil where flow separation begins at high angle of attack to preventor minimize separation. This may be driven by needing to stably achievecertain angles of attack or it may provide a better overall lift-dragcase depending on how pervasive and significant flow separation isacross the multiple flow regimes and angles of attack.

In another aspect, a designer may only optimize an airfoil for one flowregime and angle of attack, given that this one flow is the primary flowregime of most/all of the aircraft's missions and that other flowregimes are still evaluated to assure that the optimization in oneregime does not cause instabilities in other flow regimes the aircraftwill experience, for example during takeoff and landing.

The benefits of the disclosed fluid-structure system are achieved byskilled implementation of engineering design methods including but notlimited to simulation of the fluid-structure interaction, calculation ofperformance parameters related to or affected by the flow, laboratorytesting of different flow features under relevant flow parameters toselect which features to use in the design and how to combine, sequence,intermix, and functionally vary them, generative design methods or otherAI or machine learning methods for design and/or optimization featuresand how they are combined, sequence, intermixed, and varied. Theoptimization or co-optimization can be performed over differentiallengths relevant to the manufacturing process. For some features madewith some additive manufacturing processes, such as surface roughness ofpowder bed laser fusion metal, a differential length as low as 100microns may be possible for optimize. For other manufacturing methodsand other features, a longer differential length is needed. For example,a small dimple built via Filament Deposition Modeling may be at minimum1000 micron across, meaning that reasonable differentiation in thefeatures may be attainable across a 2000 micron long area. These methodsare best applied to fluid structure systems where the minimum attainablefeature size is much smaller than the surface the feature is applied to.These methods are best applied to higher speed flow for the largestperformance impact.

Performance parameters impacted by these features may include but arenot limited to any parameter describing the flow of the fluid or thefluid structure interaction, including heat transfer, temperature, anddeposition due to degradation of a fluid due to heat, parameters relatedto mixing of multiple fluids, interaction of fluids with catalyticsurfaces, etc.

The above embodiments may, in combination or separately, may utilizecomputer software and/or computer hardware (to include, for example,computer-readable mediums) for any of several functions such asautomated control and state estimation, and furthermore may utilize oneor more GUIs for human interaction with modules or elements orcomponents.

Examples of the processors as described herein may include, but are notlimited to, at least one of Qualcomm® Snapdragon® 800 and 801, Qualcomm®Snapdragon® 610 and 615 with 4G LTE Integration and 64-bit computing,Apple® A7 processor with 64-bit architecture, Apple® M7 motioncoprocessors, Samsung® Exynos® series, the Intel® Core™ family ofprocessors, the Intel® Xeon® family of processors, the Intel® Atom™family of processors, the Intel Itanium® family of processors, Intel®Core® i5-4670K and i7-4770K 22 nm Haswell, Intel® Core® i5-3570K 22 nmIvy Bridge, the AMD® FX™ family of processors, AMD® FX-4300, FX-6300,and FX-8350 32 nm Vishera, AMD® Kaveri processors, Texas Instruments®Jacinto C6000™ automotive infotainment processors, Texas Instruments®OMAP™ automotive-grade mobile processors, ARM® Cortex™-M processors,ARM® Cortex-A and ARIV1926EJS™ processors, other industry-equivalentprocessors, and may perform computational functions using any known orfuture-developed standard, instruction set, libraries, and/orarchitecture.

The exemplary systems and methods of this disclosure have been describedin relation to a manipulation of surface topology of an additivelymanufactured article. However, to avoid unnecessarily obscuring thepresent disclosure, the preceding description omits a number of knownstructures and devices. This omission is not to be construed as alimitation of the scopes of the claims. Specific details are set forthto provide an understanding of the present disclosure. It should howeverbe appreciated that the present disclosure may be practiced in a varietyof ways beyond the specific detail set forth herein.

Furthermore, while the exemplary aspects, embodiments, and/orconfigurations illustrated herein show the various components of thesystem collocated, certain components of the system can be locatedremotely, at distant portions of a distributed network, such as a LANand/or the Internet, or within a dedicated system. Thus, it should beappreciated, that the components of the system can be combined in to oneor more devices or collocated on a particular node of a distributednetwork, such as an analog and/or digital telecommunications network, apacket-switch network, or a circuit-switched network. It will beappreciated from the preceding description, and for reasons ofcomputational efficiency, that the components of the system can bearranged at any location within a distributed network of componentswithout affecting the operation of the system. For example, the variouscomponents can be located in a switch such as a PBX and media server,gateway, in one or more communications devices, at one or more users'premises, or some combination thereof. Similarly, one or more functionalportions of the system could be distributed between a telecommunicationsdevice(s) and an associated computing device.

Furthermore, it should be appreciated that the various links connectingthe elements can be wired or wireless links, or any combination thereof,or any other known or later developed element(s) that is capable ofsupplying and/or communicating data to and from the connected elements.These wired or wireless links can also be secure links and may becapable of communicating encrypted information. Transmission media usedas links, for example, can be any suitable carrier for electricalsignals, including coaxial cables, copper wire and fiber optics, and maytake the form of acoustic or light waves, such as those generated duringradio-wave and infra-red data communications.

Also, while the flowcharts have been discussed and illustrated inrelation to a particular sequence of events, it should be appreciatedthat changes, additions, and omissions to this sequence can occurwithout materially affecting the operation of the disclosed embodiments,configuration, and aspects.

A number of variations and modifications of the disclosure can be used.It would be possible to provide for some features of the disclosurewithout providing others.

In yet another embodiment, the systems and methods of this disclosurecan be implemented in conjunction with a special purpose computer, aprogrammed microprocessor or microcontroller and peripheral integratedcircuit element(s), an ASIC or other integrated circuit, a digitalsignal processor, a hard-wired electronic or logic circuit such asdiscrete element circuit, a programmable logic device or gate array suchas PLD, PLA, FPGA, PAL, special purpose computer, any comparable means,or the like. In general, any device(s) or means capable of implementingthe methodology illustrated herein can be used to implement the variousaspects of this disclosure. Exemplary hardware that can be used for thedisclosed embodiments, configurations and aspects includes computers,handheld devices, telephones (e.g., cellular, Internet enabled, digital,analog, hybrids, and others), and other hardware known in the art. Someof these devices include processors (e.g., a single or multiplemicroprocessors), memory, nonvolatile storage, input devices, and outputdevices. Furthermore, alternative software implementations including,but not limited to, distributed processing or component/objectdistributed processing, parallel processing, or virtual machineprocessing can also be constructed to implement the methods describedherein.

In yet another embodiment, the disclosed methods may be readilyimplemented in conjunction with software using object or object-orientedsoftware development environments that provide portable source code thatcan be used on a variety of computer or workstation platforms.Alternatively, the disclosed system may be implemented partially orfully in hardware using standard logic circuits or VLSI design. Whethersoftware or hardware is used to implement the systems in accordance withthis disclosure is dependent on the speed and/or efficiency requirementsof the system, the particular function, and the particular software orhardware systems or microprocessor or microcomputer systems beingutilized.

In yet another embodiment, the disclosed methods may be partiallyimplemented in software that can be stored on a storage medium, executedon programmed general-purpose computer with the cooperation of acontroller and memory, a special purpose computer, a microprocessor, orthe like. In these instances, the systems and methods of this disclosurecan be implemented as program embedded on personal computer such as anapplet, JAVA® or CGI script, as a resource residing on a server orcomputer workstation, as a routine embedded in a dedicated measurementsystem, system component, or the like. The system can also beimplemented by physically incorporating the system and/or method into asoftware and/or hardware system.

Although the present disclosure describes components and functionsimplemented in the aspects, embodiments, and/or configurations withreference to particular standards and protocols, the aspects,embodiments, and/or configurations are not limited to such standards andprotocols. Other similar standards and protocols not mentioned hereinare in existence and are considered to be included in the presentdisclosure. Moreover, the standards and protocols mentioned herein, andother similar standards and protocols not mentioned herein areperiodically superseded by faster or more effective equivalents havingessentially the same functions. Such replacement standards and protocolshaving the same functions are considered equivalents included in thepresent disclosure.

The present disclosure, in various aspects, embodiments, and/orconfigurations, includes components, methods, processes, systems and/orapparatus substantially as depicted and described herein, includingvarious aspects, embodiments, configurations embodiments,sub-combinations, and/or subsets thereof. Those of skill in the art willunderstand how to make and use the disclosed aspects, embodiments,and/or configurations after understanding the present disclosure. Thepresent disclosure, in various aspects, embodiments, and/orconfigurations, includes providing devices and processes in the absenceof items not depicted and/or described herein or in various aspects,embodiments, and/or configurations hereof, including in the absence ofsuch items as may have been used in previous devices or processes, e.g.,for improving performance, achieving ease and\or reducing cost ofimplementation.

The foregoing discussion has been presented for purposes of illustrationand description. The foregoing is not intended to limit the disclosureto the form or forms disclosed herein. In the foregoing DetailedDescription for example, various features of the disclosure are groupedtogether in one or more aspects, embodiments, and/or configurations forthe purpose of streamlining the disclosure. The features of the aspects,embodiments, and/or configurations of the disclosure may be combined inalternate aspects, embodiments, and/or configurations other than thosediscussed above. This method of disclosure is not to be interpreted asreflecting an intention that the claims require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive aspects lie in less than all features of a singleforegoing disclosed aspect, embodiment, and/or configuration. Thus, thefollowing claims are hereby incorporated into this Detailed Description,with each claim standing on its own as a separate preferred embodimentof the disclosure.

Moreover, though the description has included description of one or moreaspects, embodiments, and/or configurations and certain variations andmodifications, other variations, combinations, and modifications arewithin the scope of the disclosure, e.g., as may be within the skill andknowledge of those in the art, after understanding the presentdisclosure. It is intended to obtain rights which include alternativeaspects, embodiments, and/or configurations to the extent permitted,including alternate, interchangeable and/or equivalent structures,functions, ranges or steps to those claimed, whether or not suchalternate, interchangeable and/or equivalent structures, functions,ranges or steps are disclosed herein, and without intending to publiclydedicate any patentable subject matter.

What is claimed is:
 1. A method of additively manufacturing an articlewith a surface topology, the method comprising: determining a set ofdesign objectives for the article; assembling a set of candidate surfacetopology designs; quantifying a set of performance measurementsassociated with each of the set of candidate surface topology designs;categorizing each of the candidate surface topology designs of the setof candidate surface topology designs with respect to the set of designobjectives when the candidate surface topology design is implemented ata first particular article location; selecting a first surface topologydesign from the set of candidate surface topology designs; generating afirst set of additive manufacturing specifications to implement thefirst surface topology design at the first particular article location;and additively manufacturing the article comprising the first surfacetopology design implemented at the first particular article location. 2.The method of claim 1, wherein the article is a fluid manifold.
 3. Themethod of claim 2, wherein the fluid manifold is a Liquid Rocket Enginefluid manifold.
 4. The method of claim 1, wherein the article is anaerodynamic article.
 5. The method of claim 1, wherein the set ofperformance measurements comprise experimentally generated performancemeasurements.
 6. The method of claim 1, wherein the set of candidatesurface topology designs comprise a corrugated design.
 7. The method ofclaim 1, further comprising the steps of: selecting a second surfacetopology design from the set of candidate surface topology designs; andgenerating a second set of additive manufacturing specifications toimplement the second surface topology design at the second particulararticle location; wherein: the step of additively manufacturing thearticle further comprises the second surface topology design implementedat the second particular article location.
 8. The method of claim 1,wherein the set of performance measurements comprise a fluid frictionloss value and a heat transfer value.
 9. An article with a surfacetopology comprising: a first particular article location and a secondparticular article location; and a set of article design objectivesassociated at least with each of the first particular article locationand the second particular article location; wherein: a first surfacetopology design is implemented at the first particular article location,the first surface topology design selected from a set of candidatesurface topology designs, the first surface topology design having afirst set of additive manufacturing specifications associated withsatisfying the set of article design objectives associated with thefirst particular article location; and the article is additivelymanufactured using the first set of additive manufacturingspecifications to implement the first surface topology design at thefirst particular article location.
 10. The article of claim 9, whereinthe article is a fluid manifold.
 11. The article of claim 9, wherein thefluid manifold is a Liquid Rocket Engine fluid manifold.
 12. The articleof claim 9, wherein the article is an aerodynamic article.
 13. Thearticle of claim 9, wherein: the article is a structure defining anenclosed cavity, the first surface topology design formed on a firstinterior portion of the article; and the set of article designobjectives comprise a first fluid friction loss value and a first heattransfer value, each associated with the first interior portion of thearticle.
 14. The article of claim 9, wherein: the article is a structuredefining an enclosed cavity, the first surface topology design formed ona first exterior portion of the article and the second particularcandidate surface design formed on a second exterior portion of thearticle; and the set of article design objectives comprise a first fluidfriction loss value and a first heat transfer value, each associatedwith the first exterior portion of the article.
 15. The article of claim9, wherein the first surface topology design comprises at least one ofroughness features and porosity features.
 16. The article of claim 9,wherein the first surface topology design comprises at least one ofdimple features and grooved channel features.
 17. The article of claim9, wherein the set of candidate surface topology designs comprise acorrugated design.
 18. The article of claim 9, wherein: a second surfacetopology design is implemented at the second particular articlelocation, the second surface topology design selected from the set ofcandidate surface topology designs, the second surface topology designhaving a second set of additive manufacturing specifications associatedwith satisfying the set of article design objectives associated with thesecond particular article location; and the article is additivelymanufactured using the second set of additive manufacturingspecifications to implement the second surface topology design at thesecond particular article location.
 19. An article configured tointeract with a fluid; the article comprising: an article surfacecomprising a first article surface with a first surface topology and asecond article surface with a second surface topology; a set of articledesign objectives associated at least with each of the first articlesurface and the second article surface; wherein: a first surfacetopology design is implemented at the first article surface, the firstsurface topology design selected from a set of candidate surfacetopology designs, the first surface topology design having a first setof additive manufacturing specifications associated with the set ofarticle design objective; and the article is additively manufacturedusing the first set of additive manufacturing specifications toimplement the first surface topology design on the first articlesurface.
 20. The article of claim 19, wherein the article surface is aninterior surface of the article.